Effect of interleukin-2 on intracellular calcium levels in rat ventricular myocytes during anoxia and reoxygenation / 中国病理生理杂志

ABSTRACT

AIM: To investigate the effect of interleukin-2 (IL-2) on the intracellular calcium in electrically stimulated adult rat ventricular myocytes during anoxia and reoxygenation. METHODS: The isolated cardiac ventricular myocytes were exposed to 5 min anoxia followed by 10 min reoxygenation. Chemical anoxia was introduced by Krebs-Henseleit (K-H) solution containing 10 -3 mol/L sodium dithionite. The spectrofluorometric method was used to verify intracellular calcium transient with fura-2/AM as calcium fluorescence probe. RESULTS: It was shown that during anoxia, the amplitude of Ca 2+ transient was decreased, diastolic [Ca 2+ ] i, time to peak and time to relaxation of Ca 2+ transient were increased. All the parameters were got back but did not returned to the pre-anoxia level during reoxygenation. IL-2 at 2?10 5 U/L administrated during anoxia aggravated the effect of rexoxygenation on [Ca 2+ ] i transient. Pretreatment with a specific ? opioid antagonist, nor-BNI (10 -8 mol/L), abolished the effect induced by IL-2 during anoxia on the [Ca 2+ ] i transients, whereas specific ? opioid antagonist, naltrindole (10 -6 mol/L), did not cancel the effect. CONCLUSION: It is concluded that administration of IL-2 during anoxia aggravated the effect of reoxygenation on the [Ca 2+ ] i transients of isolated ventricular myocytes, which was mediated by cardiac ? opioid receptor pathway.